AN8 Airframe Bolt - Drilled Head, 1/2-20 Thread

AN8H bolts have a drilled head for safety wire and a 1/2-20 thread with 0.680 inch thread length.

A or no A? AN bolts were originally designed to be used with a castle nut and cotter pin, so the base part number indicates a drilled shank. The addition of an "A" at the end (for example, AN8H-20A) indicates an undrilled shank for use with a self-locking nut.